Satellite-aided systems offer the possibility of a large-area supply. With this, the service may be made available everywhere. This is especially advantageous for broadcast applications or large-area data distribution services. Satellite systems are particularly suitable for reception with a direct line-off-sight to the satellite and for mobile reception in the car. For receivers in a house and partly also for hand-held applications, the field strength of the satellite signals is often insufficient. In order to guarantee the availability of the signal also in cities or within buildings, terrestrial transmitters are used which then make the signal available with a significantly higher field strength in densely built-up areas, for example.
On the other hand, terrestrial systems have the advantage that in each region, different information is emitted and data are emitted, for example, which are relevant for only one region.